Field of the Invention
The invention relates to a flat tube, in particular for a heat exchanger, having a flat material strip having two mutually opposing first and second side walls that are connected to one another via third and fourth side walls. The invention also relates to a heat exchanger having such a flat tube.
Description of the Background Art
Flat tubes for heat exchangers are known in many configurations in the prior art. For instance, extruded flat tubes having a plurality of bars for forming individual fluid channels for capacitors or evaporators have been known for some time.
So-called bridge tubes, in which a metal strip is folded over to create for instance a single or multi-chamber tube, such as for instance a B tube, are also known. These folded tubes are typically first sealed using the soldering process for soldering the entire heat exchanger and have at least one or two fluid chambers through which a medium can flow.
DE 102006054814 A1, which corresponds to US 20110005738, discloses a soldered flat tube for capacitors or evaporators in which the tube is formed from two half shells that overlap on the short sides and are soldered there, wherein a fin is arranged in the interior space such that this fin is also positioned in the overlapping tube area and is soldered to the tube wall there.
However, there are problems with this example with respect to the complexity of manufacture and with respect to the resulting costs, since production of the multi-part tube with interior fin means increased production complexity, both in the manufacture and in the assembly of at least three parts that are joined to create one tube.
DE 102006050319 A1, which corresponds to US 20070095514, discloses a flat tube that is formed from a sheet metal strip, wherein the sheet metal strip is bent such that the closure of the sheet metal strip is arranged at a short side of the tube. Likewise arranged in the interior of the tube is a fin that is accommodated in the region of the connection of the sheet side edges between these side edges.
This tube design has drawbacks with respect to space requirements, because the lateral closure of the tube limits the space that is available for the interior of the tube.
EP 1243884 A2, which corresponds to US 20040182559, discloses a flat tube that is formed from a sheet metal strip, wherein a center bar is provided that is formed by a hook-like molding of the edge regions of the sheet metal strip, wherein a corrugated fin is arranged in the interior space of the tube.
The tube design in EP 1243884 A2 suffers from the drawback that the interior pressure stability is not optimal, especially in the central region of the bar, and during use under higher pressures there can be leaks, especially in the region of the solder point.